1. Field of the Invention
The present invention relates to a disk-shaped information recording medium for recording and reproducing information on a sector by sector basis and an information recording and reproducing apparatus using said information recording medium.
2. Description of the Prior Art
In a disk-shaped information recording medium having a large number of concentrically or spirally formed tracks, and having a disk format in which these tracks are divided into plural zones in the radial direction of disk, the same number of sectors are formed in each track in the zone, and the number of sectors formed per track increases as the zone goes from the inner periphery to the outer periphery. Such a format is called an MCAV (Modified Constant Angular Velocity) format.
FIG. 12 shows a schematic view of conventional information recording medium having an MCAV format. In the information recording medium, the data recording area in which the user can make recording is divided into plural zones. In FIG. 12, only the adjacent two zones are illustrated. While each track in the zone (i) is divided into (n+1) sectors, each track in the zone (i+1) is divided into n sectors. FIG. 13 is a track construction view in the boundary area between the zone (i) and the zone (i+1) in the disk having such an MCAV format. In FIG. 13, the track (i) is a track positioned at the innermost periphery in the zone (i), and the track (i+1) is a track positioned at the outermost periphery in the zone (i+1). And, while the track (j) is divided into n+1 sectors, the track (j+1) is divided into n sectors. Each sector is composed of an ID field in which address information is recorded and data field in which the user data are recorded.
However, in a disk of such an MCAV format, in the track positioned at the boundary of each zone, the position of ID field of the sector other than the sector S.sub.0 differs from that of the adjacent track. Accordingly, when the recording and reproducing head is positioned at the data field of the sector in which no data is recorded in these boundery tracks, address information may reproduced from the ID field on the adjacent track due to crosstalk. For example, notwithstanding the fact that the recording and reproducing head is passing in the data field of the sector S.sub.1 which exists on the track (j+1) in which no data is recorded, at the rear end of the data field, erroneous address information may be reproduced by the crosstalk from the ID field of the sector S.sub.2 in the adjacent track (j).
When such a situation occurs, data recording and reproducing operation is activated on the basis of the erroneously reproduced address information from the adjacent track, so that there is a problem that the normal data recording and reproducing operation cannot be executed.